|Year : 2019 | Volume
| Issue : 1 | Page : 19-22
Prevalence and antibiotic resistance pattern of Metallo-β-lactamase-producing Pseudomonas aeruginosa isolates from clinical specimens in a tertiary care hospital
Vinita Choudhary, Nita Pal, Saroj Hooja
Department of Microbiology, SMS Medical College, Jaipur, Rajasthan, India
|Date of Web Publication||14-Mar-2019|
Dr. Nita Pal
82, Green Nagar, Durgapura, Jaipur - 302 018, Rajasthan
Source of Support: None, Conflict of Interest: None
Background: Pseudomonas aeruginosa is emerging as a nosocomial pathogen by producing metallo-β-lactamases (MBLs) and acquiring resistance to many antimicrobial agents. The infections caused by metallo-beta-lactamases producing P. aeruginosa (MBL-PA) are associated with higher rates of mortality, morbidity, and overall healthcare costs. Aim: The aim of the study was to find the incidence of MBL in P. aeruginosa isolates and their antimicrobial resistance pattern. Material and Methods: A total of 180 non-duplicate P. aeruginosa isolates from various clinical specimens between April 2016 and March 2017 were subjected to susceptibility testing by disc diffusion test as per the Clinical and Laboratory Standards Institute guidelines 2015. Imipenem and meropenem resistant isolates were selected for the detection of MBL production by disc potentiation test and modified Hodge test. Results: Out of 180 isolates of P. aeruginosa, MBL was detected in 36 (20.00%) isolates. Resistance was significantly higher in the MBL-PA with 94.44% resistance to aztreonam followed by cefoxitin (91.66%), piperacilline/tazobactam and cefepime (80.55%). The prevalence of multidrug-resistant and possible extensively drug-resistant isolates was significantly higher among the MBL group as compared to that in the non-MBL group [50.00% vs. 11.11% and 5.55% vs. 0.69% (P = <0.05)]. None of the isolates were pan drug resistant. Conclusions: Increasing prevalence of MBL-PA producing isolates in hospital settings makes it important to perform routine detection of MBL strains for the purpose of infection control and for minimizing the adverse outcome of infection.
Keywords: Metallo-β-lactamase, multidrug resistance, Pseudomonas aeruginosa
|How to cite this article:|
Choudhary V, Pal N, Hooja S. Prevalence and antibiotic resistance pattern of Metallo-β-lactamase-producing Pseudomonas aeruginosa isolates from clinical specimens in a tertiary care hospital. J Mahatma Gandhi Inst Med Sci 2019;24:19-22
|How to cite this URL:|
Choudhary V, Pal N, Hooja S. Prevalence and antibiotic resistance pattern of Metallo-β-lactamase-producing Pseudomonas aeruginosa isolates from clinical specimens in a tertiary care hospital. J Mahatma Gandhi Inst Med Sci [serial online] 2019 [cited 2023 Mar 29];24:19-22. Available from: https://www.jmgims.co.in/text.asp?2019/24/1/19/254123
| Introduction|| |
The genus Pseudomonas belongs to the family Pseudomonadaceae and consists of aerobic, Gram-negative, nonfermentative, nonsporing, and oxidase positive bacilli. Pseudomonas aeruginosa is an important cause of nosocomial infections and causes infections ranging from urinary tract infection to severe sepsis. For severe Pseudomonas infections, carbapenems are the antibiotics of choice, but resistance to carbapenem resistance is increasing worldwide mostly due to the production of metallo-β-lactamases (MBLs). P. aeruginosa-producing MBL (MBL-PA) was first reported from Japan in 1991. The present study was undertaken to find out the prevalence and antimicrobial resistance pattern of MBL-PA in our institution.
| Materials and Methods|| |
The present study was carried out in the department of microbiology, from April 2016 to March 2017. A total of 180 nonlactose fermenting, oxidase positive, and Gram-negative bacilli isolated from various clinical specimens such as pus, blood, sputum, throat swab, ear swab, cerebrospinal fluid, urine, pleural fluid, and corneal swab were included in the study. The isolates were confirmed by Grams staining, biochemical tests, pigment production (chloroform test), and growth at 42°C. Antibiotic susceptibility testing was done on Mueller–Hinton agar by Kirby–Bauer disc-diffusion method and the results interpreted as per the Clinical Laboratory Standards Institute 2015 criteria. Antimicrobial susceptibility testing was done with gentamicin (10 μg), amikacin (30 μg), imipenem (10 μg), meropenem (10 μg), ceftazidime (30 μg), cefepime (30 μg), ciprofloxacin (5 μg), levofloxacin (5 μg), ticarcillin-clavulanic acid (75/10 μg), piperacillin-tazobactam (100/10 μg), aztreonam (30 μg), colistin (10 μg), and polymyxin B (300 unit).
- Multidrug resistant (MDR) – Resistance to ≥1 agent in ≥3 antimicrobial categories
- Extensively drug resistant (XDR) – Resistance to ≥1 agent in all but <2 categories
- Pandrug resistant (PDR) – Resistance to all antimicrobial agents listed.
Isolates showing resistance to imipenem and meropenem (inhibition zone <19 mm) by disc-diffusion method were considered as potential MBL producers and further confirmed by disc-potentiation test and modified Hodge test (MHT).
Statistical analysis was done using computer software Primer. The qualitative data were expressed in proportion and percentages and the quantitative data were expressed as mean and standard deviations. The difference in proportion was analyzed using Chi-square test. Significance level for tests was determined as 95% (P < 0.05).
| Results|| |
During the study period, a total of 180 isolates of P. aeruginosa were collected. Out of 180 isolates of P. aeruginosa, 61 (33.88%) were resistant to imipenem; MBL-PA was detected by disc potentiation test and MHT in 36 (20%) isolates. The demographic comparison of patients infected with MBL-PA and non-MBL-PA isolates is shown in [Table 1]. Out of 36 MBL-PA, 25 isolates (69.44%) were recovered from male patients and 11 isolates (30.55%) were recovered from female patients. Among 144 non-MBL-PA isolates, 87 (60.41%) were recovered from males and 57 (39.58%) were recovered from females. For both the groups, the isolates were obtained most commonly from the 21 to 40 year age group (41.66%), followed by the 41–60-year-age group (20%). There was no statistical difference between the mean age of patients for MBL-PA (33.85 ± 15.03 years) and non-MBL-PA (32.97 ± 17.95 years) isolates (P = 0.847). The most common specimen source for both MBL-producing and non-MBL-PA was pus (36.11% and 20.83%, respectively) [Table 2]. MBL-producing P. aeruginosa was isolated from 88.11% (32/36) inpatients and 11.11% (4/36) outpatients, while non-MBL-PA was obtained from 85.41% (123/144) inpatients and 14.58% (21/144) outpatients respectively (P = 0.788).
|Table 1: Sex and age group distribution of metallo-β-lactamase and nonmetallo-β-lactamase producing Pseudomonas aeruginosa isolates|
Click here to view
|Table 2: Distribution of metallo-β-lactamase and nonmetallo-β-lactamase producing Pseudomonas aeruginosa isolates among various specimens|
Click here to view
[Table 3] compares the results of antibiogram for routinely tested antipseudomonal agents of MBL-PA and non-MBL-PA isolates. The MBL-PA isolates showed highest resistance to aztreonam (94.44%) followed by cefoxitin (91.66%), piperacillin/tazobactam (80.55%), and cefepime (80.55%), while resistance among non-MBL-PA isolates was 79.86% to cefoxitin, 60.41% to aztreonam, 50.69% to cefepime 38.88% to cefoxitin, 38.88% piperacillin/tazobactam and 17.38% to imipenem. Resistance to all the antibiotics used in the study, except ticarcillin-clavulanic acid, aztreonam, polymyxin B, and colistin was significantly more in the MBL-PA strains, compared to that in the non-MBL-PA strains. The prevalence of MDR and possible XDR isolates was significantly higher among the MBL group as compared to that in the non-MBL group (50% vs. 11.11% and 5.55% vs. 0.69% (P = <0.05)] [Table 4]. None of the isolates were PDR.
|Table 3: Antibiotic resistance pattern of metallo-β-lactamase and nonmetallo-β-lactamase producing Pseudomonas aeruginosa isolates|
Click here to view
|Table 4: Prevalence of multidrug resistance and possible extensively drug resistance among metallo-β-lactamase and nonmetallo-β-lactamase producing Pseudomonas aeruginosa isolates|
Click here to view
| Discussion|| |
The occurrence of MDR MBL-PA isolates in a hospital setting is of concern as it poses a problem in therapy and infection control management. In our study, the prevalence of MBL-PA isolates was 20%, while in a previous study from the same hospital (2012), a prevalence of 18.37% was reported by Sachdeva et al. Kumar et al. reported a prevalence of 20% from the same region, while Agarwal et al. reported a prevalence of 11.81%. In India, the prevalence rate of MBL-PA has been reported to vary from 11% to 25%. A similar prevalence rate of MBL-PA has been observed in various studies conducted by Kali et al. (16.32%), Gupta et al. (14.3%), Ranjan et al. (16.72%), Chaudhary et al. (16.89%), and Chauhan et al. (19.15%). Compared to these findings, other studies have reported a lower prevalence of 5.5% by Thapa et al., 8.7% by Chaudhary et al. 11.66% by Deeba et al., and 15.38% by Senthamarai et al. Two studies from Uttarakhand and Puducherry reported higher prevalence of 38.6% and 50.5%, respectively. Variation in the detection rates of MBLs reported previously can be attributed to several factors that include geographical locations, infection control practices, number of samples tested, and methods used to detect MBLs.
In the present study, MBL-PA was detected in 20% (36/180) isolates, of which 88.88% (32/36) isolates were from inpatients and 11.11% (4/36) were from outpatients. However, no significant difference was observed according to patient admission status between MBL-PA and non-MBL-PA (P = 0.788). Most of the studies have reported higher prevalence of MBL-PA isolates from inpatients.,,,
In the present study, MBL-PA was predominantly isolated from pus 13 (36.11%), followed by endotracheal secretions 7 (30.43%) and urine 7 (19.44%). The same has been reported by Ranjan et al., Deeba et al., and Anuradha et al., while Chaudhary observed MBL-PA isolates more from blood specimens. Male preponderance 112 (62.22%) was noted in this study. Similar observations were made by Senthamarai et al. and Ranjan et al. Only in one study from Nepal, female preponderance of 55.17% was reported. Outdoor activity, personal habits, nature of work, and exposure to areas, which are inhabited by organisms could be the reasons for male preponderance. Majority of the isolates (41.66%) were obtained from patients between 21 and 40 years which is in accordance with other studies.,,
Our study has illustrated that the MBL-PA strains were more resistant to commonly used antimicrobial agents. MBL-PA isolates showed the highest resistance to aztreonam (94.44%) followed by cefoxitin (91.66%), piperacillin/tazobactam, and cefepime (80.55%). Several studies have also highlighted greater resistance exhibited by MBL-PA strains toward almost all classes of antimicrobials, as compared to non-MBL-PA strains. Resistance to colistin among MBL-PA in the present study was 2.77%, while Anuradha et al. reported no resistance and Kumar et al. 5%. Deeba et al. and Kumar et al. observed no polymyxin B-resistant MBL-PA isolates, but in the present study, 2.77% isolates were resistant.
The prevalence of MDR isolates in our study was significantly higher in the MBL-PA (44.44%) as compared to the non-MBL-PA (5.55%) (P ≤ 0.05). A similar result was found in a study conducted by Ranjan et al., in which 55.17% of the MBL-PA strains were MDR, whereas 8.62% were non-MBL-PA. Ranjan et al. reported PDR among 7.88% MBL-PA strains and 0.68% in non-MBL-PA strains; however, in the present study no PDR strains were isolated. The significantly higher prevalence of multidrug and possible XDR among MBLPA strains, as compared to that in non-MBL-PA strains, supports the notion that clinical microbiological laboratories must be able to distinguish MBL-PA strains from those with other mechanisms responsible for carbapenem resistance. The identification of MBL-PA isolates also has clinical implications, because such isolates are more likely to cause invasive disease and are associated with a higher hospital case fatality rate, compared with other imipenem-resistant isolates.,
| Conclusion|| |
Worldwide increase in the occurrence of MBL-PA is alarming. They also possess intrinsic resistance to many antibiotics, develop resistance by mutations, and participate in horizontal MBL gene transfer with other pathogens. Early detection is therefore crucial for the treatment with alternative antimicrobials and timely implementation of strict infection control practices. There is no standardized method for MBL detection, though detection by polymerase chain reaction is highly accurate and reliable, but its accessibility is often limited to reference laboratories. Thus, laboratory methods including culture and antimicrobial susceptibility testing with routine screening for MBL production should be done for proper diagnosis and management of all P. aeruginosa infections.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Koneman EW, Allen SD, Janda WM, Schreckenberger PC, Winn WC. Color Atlas and Textbook of Diagonostic Microbiology. 6th
ed. Philadelphia, USA: Lippincott Raven Publishers; 1997.
Pollack M. P. aeruginosa
. In: Mandell GL, Dolan R, Bennett JE, editors. Principles and Practices of Infectious Diseases. New York: Churchill Livingstone; 1995.
Hammami S, Boutiba-Ben Boubaker I, Ghozzi R, Saidani M, Amine S, Ben Redjeb S, et al.
Nosocomial outbreak of imipenem-resistant Pseudomonas aeruginosa
producing VIM-2 metallo-β-lactamase in a kidney transplantation unit. Diagn Pathol 2011;6:106.
Bhongle NN, Nagdeo NV, Thombare VR. The prevalence of metallo β-lactamases in the clinical isolates of Pseudomonas aeruginosa
in a tertiary care hospital: An alarming threat. J Clin Diagn Res 2012;6:1200-2.
Clinical and Laboratory Standards Institute. The Performance Standards for the Antimicrobial Disc Susceptibility Tests. M100-S25. Wayne PA: Clinical and Laboratory Standards Institute; 2015.
Magiorakos AP, Srinivasan A, Carey RB, Carmeli Y, Falagas ME, Giske CG, et al.
Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: An international expert proposal for interim standard definitions for acquired resistance. Clin Microbiol Infect 2012;18:268-81.
Dahiya S, Singla P, Chaudhary U, Singh B. Carbapenemases: A review. Int J Adv Health Sci 2015;2:11-7.
Sachdeva R, Sharma B, Sharma R. Evaluation of different phenotypic tests for detection of metallo-β-lactamases in imipenem-resistant Pseudomonas aeruginosa
. J Lab Physicians 2017;9:249-53.
] [Full text]
Kumar R, Srivastva P, Rishi S, Dahiya SS, Hemwani K, Nirwan PS. Detection and antimicrobial susceptibility pattern of P. aeruginosa
isolates in various clinical samples with special reference to metallo-beta-lactamase from a tertiary care hospital in Jaipur, India. Natl J Med Res 2014;4:128-31.
Agarwal S, Durlabhji P, Gupta S, Mittal J, Dalela G. Incidence of metallo-β-lactamase producing P. aeruginosa
isolates and their antimicrobial susceptibility pattern in clinical samples from a tertiary care hospital. Int J Res Rev 2017;4:92-8.
Kali A, Srirangaraj S, Kumar S, Divya HA, Kalyani A, Umadevi S, et al.
Detection of metallo-beta-lactamase producing Pseudomonas aeruginosa
in Intensive Care Units. Australas Med J 2013;6:686-93.
Gupta R, Malik A, Rizvi M, Ahmed M. Presence of metallo-beta-lactamases (MBL), extended-spectrum beta-lactamase (ESBL) and AmpC positive non-fermenting Gram-negative bacilli among Intensive Care Unit patients with special reference to molecular detection of blaCTX-M and blaAmpC genes. Indian J Med Res 2016;144:271-5.
] [Full text]
Ranjan S, Banashankari G, Babu PS. Comparison of epidemiological and antibiotic susceptibility pattern of metallo-beta-lactamase-positive and metallo-beta-lactamase-negative strains of Pseudomonas aeruginosa
. J Lab Physicians 2014;6:109-13.
] [Full text]
Chaudhary M, Payasi A. Rising antimicrobial resistance of P. aeruginosa
isolated from clinical specimens in India. J Proteomics Bioinform 2013;6:5-9.
Chauhan R, Sharma PC. Phenotypic detection of metallo-β-lactamase (MBL) producers among multidrug resistant (MDR) strains of P. aeruginosa
in Himachal Pradesh. Indian J Basic Appl Med Res 2013;3:303-13.
Thapa P, Bhandari D, Shrestha D, Parajuli H, Chaudhary P, Amatya J, et al.
Ahospital based surveillance of metallo-beta-lactamase producing Gram-negative bacteria in Nepal by imipenem-EDTA disk method. BMC Res Notes 2017;10:322.
Deeba B, Manzoor AT, Bashir AF, Bashir G, Danish Z, Shabir A, et al
. Detection of metallo-beta-lactamase (MBL) producing P. aeruginosa
at a tertiary care hospital in Kashmir. Afr J Microbiol Res 2011;5:164-72.
Senthamarai S, Reddy AS, Sivasankari S, Anitha C, Somasunder V, Kumudhavathi MS, et al.
Resistance pattern of Pseudomonas aeruginosa
in a tertiary care hospital of Kanchipuram, Tamilnadu, India. J Clin Diagn Res 2014;8:DC30-2.
Rawat V, Singhai M, Verma PK. Detection of different β-lactamases and their co-existence by using various discs combination methods in clinical isolates of Enterobacteriaceae
spp. J Lab Physicians 2013;5:21-5.
] [Full text]
Pramodhini S, Umadevi S, Seetha KS. Prevalence of antimicrobial resistance in clinical isolates of Pseudomonas aeruginosa
in a tertiary care hospital, Puducherry, India. Int J Curr Microbiol Appl Sci 2015;4:718-26.
Umadevi S, Joseph NM, Kumari K, Easow JM, Kumar S, Stephen S, et al.
Detection of extended spectrum beta lactamases, Ampc beta lactamases and metallobetalactamases in clinical isolates of ceftazidime resistant Pseudomonas aeruginosa
. Braz J Microbiol 2011;42:1284-8.
Anuradha B, Afreen U, Praveena M. Evaluation of antimicrobial susceptibility pattern of P. aeruginosa
with special reference to MBL production in a tertiary care hospital. Global J Med Res 2014;14:17-22.
Chander A, Raza MS. Antimicrobial susceptibility patterns of Pseudomonas aeruginosa
clinical isolates at a tertiary care hospital in Kathmandu, Nepal. Asian J Pharm Clin Res 2013;6:235-8.
[Table 1], [Table 2], [Table 3], [Table 4]
|This article has been cited by|
||Study of quorum-sensing LasR and RhlR genes and their dependent virulence factors in Pseudomonas aeruginosa isolates from infected burn wounds
| ||Aya Ahmad Elnegery,Wafaa Kamel Mowafy,Tarek Ahmed Zahra,Noha Tharwat Abou El-Khier |
| ||Access Microbiology. 2021; |
|[Pubmed] | [DOI]|
||ANTIBIOTIC RESISTANCE PATTERN OF PSEUDOMONAS AERUGINOSA ISOLATED FROM VARIOUS CLINICAL SAMPLES IN A TERTIARY CARE HOSPITAL, PUDUCHERRY
| ||KANTHAKUMAR A, JAYAVARTHINNI M |
| ||Asian Journal of Pharmaceutical and Clinical Research. 2021; : 106 |
|[Pubmed] | [DOI]|
||Coordination of las regulated virulence factors with Multidrug-Resistant and extensively drug-resistant in superbug strains of P. aeruginosa
| ||Sanaz Dehbashi,Mohammad Reza Pourmand,Mohammad Yousef Alikhani,Sara Soleimani Asl,Mohammad Reza Arabestani |
| ||Molecular Biology Reports. 2020; |
|[Pubmed] | [DOI]|
||Study on Metallo-Beta Lactamase Producing Pseudomonas Species in Clinical Isolates of a Tertiary Care Hospital of Western Odisha
| ||Shuvankar Mukherjee,Suchitra Mishra,Shreekant Tiwari |
| ||Journal of Evolution of Medical and Dental Sciences. 2020; 9(19): 1533 |
|[Pubmed] | [DOI]|
Distribution of Class B and Class A ß-Lactamases in Clinical Strains of Pseudomonas aeruginosa: Comparison of Phenotypic Methods and High-Resolution Melting Analysis (HRMA) Assay
| ||Sanaz Dehbashi,Hamed Tahmasebi,Mohammad Yousef Alikhani,Fariba Keramat,Mohammad Reza Arabestani |
| ||Infection and Drug Resistance. 2020; Volume 13: 2037 |
|[Pubmed] | [DOI]|